The invention relates to a reinforcing member for a belt shaft, a belt shaft as well as an end fitting tensioner comprising such belt shaft.
A seat belt by which a vehicle occupant is restrained in an automotive vehicle, if necessary, can be wound onto the belt shaft. The belt shaft is arranged in a belt winder that may be configured in two variants.
In a first variant the belt winder is an end fitting on which the webbing is arranged and in which the belt shaft does not rotate in the normal state. Only when belt tensioning is to be performed, is the belt shaft rotated about several revolutions in a winding direction so as to remove the belt slack from the seat belt.
In a second variant, the belt winder is a belt retractor in which the belt shaft is rotatably mounted. The length of webbing required for fastening the seat belt, for example, can be wound off the belt shaft, and during unbuckling the webbing is rewound. In addition, also in the belt retractor a belt tensioner may be integrated so as to tension the seat belt if necessary. Belt shafts for belt retractors usually have a definitely larger diameter than those for end fittings.
Such belt shaft is known, for example, from DE 10 2011 117 052 A1. This belt shaft includes a body into which the reinforcing member may be hung. The body includes two flanges which are connected to a land for bearing the belt shaft. Between the flanges a recess for receiving the reinforcing member is formed. Hooking silts for hooking portions of the reinforcing member are provided at each of the flanges.
The webbing may be slipped onto the reinforcing member and, resp., a retaining portion of the reinforcing member by a sewn eye so that the webbing is safely fixed to the reinforcing member. Subsequently, the reinforcing member is hung into the hooking slits of the body. This design facilitates simple fastening of the webbing.
The known reinforcing members consist of a substantially planar sheet metal part for reasons of costs. When the webbing is wound, the webbing first wraps the land of the body and is supported by the same. The load transfer from the webbing thus is performed via the hooking slits and the land to the body. Due to the geometry of the land and, resp., the reinforcing member, a strongly irregular load, especially bending stresses, of the body and the reinforcing member are entailed. In addition, when a straight sheet metal part is used as a reinforcing member, the belt shaft is not completely round so that imbalance may occur when the webbing is wound.